PodTopologySpread excludes terminatingPods when making scheduling decision

pkg/scheduler/core/generic_scheduler_test.go

@@ -611,7 +611,7 @@ func TestGenericScheduler(t *testing.T) {
 			wErr:  fmt.Errorf("error while running score plugin for pod \"2\": %+v", errPrioritize),
 		},
 		{
-			name: "test even pods spread predicate - 2 nodes with maxskew=1",
+			name: "test podtopologyspread plugin - 2 nodes with maxskew=1",
 			registerPlugins: []st.RegisterPluginFunc{
 				st.RegisterQueueSortPlugin(queuesort.Name, queuesort.New),
 				st.RegisterPluginAsExtensions(
@@ -659,7 +659,7 @@ func TestGenericScheduler(t *testing.T) {
 			wErr:          nil,
 		},
 		{
-			name: "test even pods spread predicate - 3 nodes with maxskew=2",
+			name: "test podtopologyspread plugin - 3 nodes with maxskew=2",
 			registerPlugins: []st.RegisterPluginFunc{
 				st.RegisterQueueSortPlugin(queuesort.Name, queuesort.New),
 				st.RegisterPluginAsExtensions(
@@ -854,7 +854,6 @@ func makeScheduler(nodes []*v1.Node, fns ...st.RegisterPluginFunc) *genericSched
 		schedulerapi.DefaultPercentageOfNodesToScore, false)
 	cache.UpdateSnapshot(s.(*genericScheduler).nodeInfoSnapshot)
 	return s.(*genericScheduler)
-
 }
 
 func TestFindFitAllError(t *testing.T) {

pkg/scheduler/framework/plugins/podtopologyspread/filtering.go

@@ -255,7 +255,8 @@ func calPreFilterState(pod *v1.Pod, allNodes []*schedulernodeinfo.NodeInfo) (*pr
 			matchTotal := int32(0)
 			// nodeInfo.Pods() can be empty; or all pods don't fit
 			for _, existingPod := range nodeInfo.Pods() {
-				if existingPod.Namespace != pod.Namespace {
+				// Bypass terminating Pod (see #87621).
+				if existingPod.DeletionTimestamp != nil || existingPod.Namespace != pod.Namespace {
 					continue
 				}
 				if constraint.selector.Matches(labels.Set(existingPod.Labels)) {

pkg/scheduler/framework/plugins/podtopologyspread/filtering_test.go

@@ -491,7 +491,7 @@ func TestPreFilterStateAddPod(t *testing.T) {
 			},
 		},
 		{
-			name: "add a pod with mis-matched namespace doesn't change topologyKeyToMinPodsMap",
+			name: "add a pod in a different namespace doesn't change topologyKeyToMinPodsMap",
 			preemptor: st.MakePod().Name("p").Label("foo", "").
 				SpreadConstraint(1, "node", hardSpread, st.MakeLabelSelector().Exists("foo").Obj()).
 				Obj(),
@@ -1036,7 +1036,7 @@ func TestSingleConstraint(t *testing.T) {
 			},
 		},
 		{
-			name: "existing pods with mis-matched namespace doesn't count",
+			name: "existing pods in a different namespace do not count",
 			pod: st.MakePod().Name("p").Label("foo", "").SpreadConstraint(
 				1, "zone", hardSpread, st.MakeLabelSelector().Exists("foo").Obj(),
 			).Obj(),
@@ -1225,6 +1225,24 @@ func TestSingleConstraint(t *testing.T) {
 				"node-y": false,
 			},
 		},
+		{
+			name: "terminating Pods should be excluded",
+			pod: st.MakePod().Name("p").Label("foo", "").SpreadConstraint(
+				1, "node", hardSpread, st.MakeLabelSelector().Exists("foo").Obj(),
+			).Obj(),
+			nodes: []*v1.Node{
+				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
+				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
+			},
+			existingPods: []*v1.Pod{
+				st.MakePod().Name("p-a").Node("node-a").Label("foo", "").Terminating().Obj(),
+				st.MakePod().Name("p-b").Node("node-b").Label("foo", "").Obj(),
+			},
+			fits: map[string]bool{
+				"node-a": true,
+				"node-b": false,
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

pkg/scheduler/framework/plugins/podtopologyspread/scoring.go

@@ -135,6 +135,10 @@ func (pl *PodTopologySpread) PostFilter(
 			// <matchSum> indicates how many pods (on current node) match the <constraint>.
 			matchSum := int64(0)
 			for _, existingPod := range nodeInfo.Pods() {
+				// Bypass terminating Pod (see #87621).
+				if existingPod.DeletionTimestamp != nil || existingPod.Namespace != pod.Namespace {
+					continue
+				}
 				if c.selector.Matches(labels.Set(existingPod.Labels)) {
 					matchSum++
 				}

pkg/scheduler/framework/plugins/podtopologyspread/scoring_test.go

@@ -429,6 +429,44 @@ func TestPodTopologySpreadScore(t *testing.T) {
 				{Name: "node-x", Score: 100},
 			},
 		},
+		{
+			name: "existing pods in a different namespace do not count",
+			pod: st.MakePod().Name("p").Label("foo", "").
+				SpreadConstraint(1, "node", softSpread, st.MakeLabelSelector().Exists("foo").Obj()).
+				Obj(),
+			existingPods: []*v1.Pod{
+				st.MakePod().Name("p-a1").Namespace("ns1").Node("node-a").Label("foo", "").Obj(),
+				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
+				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
+				st.MakePod().Name("p-b2").Node("node-b").Label("foo", "").Obj(),
+			},
+			nodes: []*v1.Node{
+				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
+				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
+			},
+			want: []framework.NodeScore{
+				{Name: "node-a", Score: 100},
+				{Name: "node-b", Score: 50},
+			},
+		},
+		{
+			name: "terminating Pods should be excluded",
+			pod: st.MakePod().Name("p").Label("foo", "").SpreadConstraint(
+				1, "node", softSpread, st.MakeLabelSelector().Exists("foo").Obj(),
+			).Obj(),
+			nodes: []*v1.Node{
+				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
+				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
+			},
+			existingPods: []*v1.Pod{
+				st.MakePod().Name("p-a").Node("node-a").Label("foo", "").Terminating().Obj(),
+				st.MakePod().Name("p-b").Node("node-b").Label("foo", "").Obj(),
+			},
+			want: []framework.NodeScore{
+				{Name: "node-a", Score: 100},
+				{Name: "node-b", Score: 0},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

pkg/scheduler/testing/wrappers.go

@@ -171,6 +171,13 @@ func (p *PodWrapper) Priority(val int32) *PodWrapper {
 	return p
 }
 
+// Terminating sets the inner pod's deletionTimestamp to current timestamp.
+func (p *PodWrapper) Terminating() *PodWrapper {
+	now := metav1.Now()
+	p.DeletionTimestamp = &now
+	return p
+}
+
 // ZeroTerminationGracePeriod sets the TerminationGracePeriodSeconds of the inner pod to zero.
 func (p *PodWrapper) ZeroTerminationGracePeriod() *PodWrapper {
 	p.Spec.TerminationGracePeriodSeconds = &zero